I'm told that Anthropic has been locking enterprise customers into contracts with a mandatory amount of spend in exchange for a minor rebate. I don't know how widespread those contracts are, but either way, my guess is that when they eventually expire, those customers will switch to e.g. DeepSeek for the 80% of workloads that don't need the extra oomph of Opus. I don't know if the numbers at that point will add up to Anthropic surviving. They do seem to be concerned, judging by how hard they seem to be pushing for regulatory capture.

Your understanding is wrong - there is no lock in.

I'm pretty sure it isn't. Or at least I should clarify: Anthropic got some orgs (Honeycomb people mentioned it for instance) on committed spend contracts, which de facto makes using non-/A models unworthwhile since the /A spend is already committed anyway. Which I'll grant you is only functionally the same as lock-in if not quite definitionally.

on the flip side, some early adopters of the tech have been scaling back or removing. Which would both offset gains from new-comers as an increase and also reduces the willingness of people to take the plunge.

There's no doubt AI companies can be profitable and bring value, but anthropic and OAI are horrifically over-valued at the moment, and there is no credible read that currently signals engaging in trade of these companies stock is anything other than engaging in greater fool theory.